This handy tool solves the problem by transforming your standard vernier caliper into a dedicated radius gauge. It is easy to read the measuring result and calculate the radius with it.

The angle on this tool is intentionally designed so that you can simply multiply the result by 3 to calculate the radius of round corner, rather than sqrt(2) or other difficult values (as shown above). I made this model with FreeCAD, you can download the file and modify it as you need.

How to Print

No support is required.

If your slicer has the “Seam Painting” feature, you can use it to hide the seam for better quality.

How to Assemble

You will need:

• 1x Printed body
• 2x Cylindrical magnet, 5mm in diameter and 3mm thick

If The holes is too tight for magnets, use a drill or knife to enlarge it. If they are too loose, use a drop of glue to fix the magnets.